164105561 has 2 divisors, whose sum is σ = 164105562. Its totient is φ = 164105560.

The previous prime is 164105521. The next prime is 164105563. The reversal of 164105561 is 165501461.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 140873161 + 23232400 = 11869^2 + 4820^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-164105561 is a prime.

It is a super-2 number, since 2×164105561² = 53861270302249442, which contains 22 as substring.

It is a Sophie Germain prime.

Together with 164105563, it forms a pair of twin primes.

It is a Chen prime.

It is a Curzon number.

It is not a weakly prime, because it can be changed into another prime (164105563) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 82052780 + 82052781.

It is an arithmetic number, because the mean of its divisors is an integer number (82052781).

Almost surely, 2^164105561 is an apocalyptic number.

It is an amenable number.

164105561 is a deficient number, since it is larger than the sum of its proper divisors (1).

164105561 is an equidigital number, since it uses as much as digits as its factorization.

164105561 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 3600, while the sum is 29.

The square root of 164105561 is about 12810.3692764885. The cubic root of 164105561 is about 547.4877832738.

The spelling of 164105561 in words is "one hundred sixty-four million, one hundred five thousand, five hundred sixty-one".